Figure eight pinion bearing support

ABSTRACT

A bearing support design configured to provide increased resistance to deflection of a crankshaft within a power end. The bearing support design is contoured in the shape of a figure eight and provides an increased surface area for supporting the crankshaft and gearing. The support may be integrally formed in the frame plate of the power end or may alternatively be retrofitted into an existing frame plate and thereby be welded in. The power end having a bearing support at each end of the crankshaft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/638,813, filed on Mar. 4, 2015, which claims priority to U.S.Provisional Patent Application Ser. No. 61/947,677, filed on Mar. 4,2014, the contents of each are herein incorporated by reference.

BACKGROUND Field

The application relates generally to power ends and, more particularly,to a bearing support located on each power end frame plate.

Description of the Related Art

It is difficult to economically produce hydrocarbons from lowpermeability reservoir rocks. Oil and gas production rates are oftenboosted by hydraulic fracturing, a technique that increases rockpermeability by opening channels through which hydrocarbons can flow torecovery wells. During hydraulic fracturing, a fluid is pumped into theearth under high pressure (sometimes as high as 50,000 PSI) where itenters a reservoir rock and cracks or fractures it. Large quantities ofproppants are carried in suspension by the fluid into the fractures.When the pressure is released, the fractures partially close on theproppants, leaving channels for oil and gas to flow.

Specialized pump systems are used to deliver fracture fluids atsufficiently high rates and pressures to complete a hydraulic fracturingprocedure or “frac job.” Positive displacement pumps used in Oil FieldWell Service Applications are operated, serviced & maintained in harshenvironments & operating conditions. These pump systems are usuallyprovided with power ends and fluid ends. Power ends induce movement of aplunger within the fluid end that places fluids under pressure. Withinthese fluid ends are a number of reciprocating plungers that pressurizefracture fluids. Suction valves and discharge valves control fluid flowto, and from, the plungers.

Power ends use large bull gears and pinion shafts to drive the power endcrankshafts and typically have large amounts of pinion shaft deflection.In use, the bull gears and pinion shafts usually deflect away from thebull gear causing excessive strain on the pinion bearings, excessivewear on the bull gear and pinion teeth, and excessive strain in thepower frames. Such deflection is seen in FIG. 1. These issues typicallyarise because narrow outer power frame plates are used (less than 1″typically). The lower weight designs commonly used struggle to supportthe dynamic separation force loads generated by the bull and pinion gearhigh loads. When failure occurs, cracks can develop in the power frameplates as seen in FIG. 3. In an attempt to strengthen the power frameplates, housings may be bolted on to hold the pinion bearings to thethin outer frame plates. However, this fails to adequately increase thestrength of the frame plates, as seen in FIGS. 2 and 3.

Although great strides have been made in power ends, considerableshortcomings remain.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are setforth in the description. However, the invention itself, as well as apreferred mode of use, and further objectives and advantages thereof,will best be understood by reference to the following detaileddescription when read in conjunction with the accompanying drawings,wherein:

FIG. 1 is a perspective view of a pinion gear and a bull gear in a powerend frame plate;

FIG. 2 is a view of the power end frame plate of FIG. 1 with a housingattached;

FIG. 3 is an enlarged view of the power end frame plate of FIG. 2, thepower end frame plate showing cracks;

FIG. 4 is a chart illustrating the deflection resulting in a crankshaftin a power end according to the preferred embodiment of the presentapplication;

FIG. 5 is an enlarged side view of the teeth of a bull gear and piniongear in operation with the power end of FIG. 4;

FIG. 6 is a diagram of the force loads acting on the bull gear andpinion gears of FIG. 5;

FIG. 7 is an orthogonal view of the frame plate as used in the power endof the preferred embodiment of the present application, the frame platehaving a figure eight bearing support;

FIG. 8 is a side and end view of the figure eight bearing support ofFIG. 7;

FIGS. 9A, 9B, and 9C are an illustration showing the figure eightbearing support inserts before and after installation into the power endframe plate;

FIG. 10 is an oblique view of a support in accordance with analternative embodiment of the present application; and

FIG. 11 is an oblique view of the support of FIG. 10 secured to a baseplate.

While the system of the present application is susceptible to variousmodifications and alternative forms, specific embodiments thereof havebeen shown by way of example in the drawings and are herein described indetail. It should be understood, however, that the description herein ofspecific embodiments is not intended to limit the invention to theparticular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the present application as described herein.

DETAILED DESCRIPTION

An illustrative embodiment of the invention is described below. In theinterest of clarity, not all features of an actual implementation aredescribed in this specification. It will of course be appreciated thatin the development of any such actual embodiment, numerousimplementation-specific decisions must be made to achieve thedeveloper's specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure.

In the specification, reference may be made to the spatial relationshipsbetween various components and to the spatial orientation of variousaspects of components as the devices are depicted in the attacheddrawings. However, as will be recognized by those skilled in the artafter a complete reading of the present application, the devices,members, apparatuses, etc. described herein may be positioned in anydesired orientation. Thus, the use of terms to describe a spatialrelationship between various components or to describe the spatialorientation of aspects of such components should be understood todescribe a relative relationship between the components or a spatialorientation of aspects of such components, respectively, as the devicedescribed herein may be oriented in any desired direction.

Referring to FIGS. 4-6 in the drawings, deflection forces exerted uponbull gears and pinion shafts configured to drive the power endcrankshafts is illustrated. As seen in FIG. 4, crankshaft 101 is shownin an unloaded position and in a loaded position under stress. Thedeflection of crankshaft 101 can be seen. Deflection is caused by thenaturally occurring separation forces that develop between the piniongear and bull gear as the teeth push against each other during highloads (See FIG. 5). As seen in FIGS. 5 and 6, gear teeth are designedusing rounded shapes that permit them to minimize friction as engagementoccurs. The rounded shape allows them to “roll” against each otherinstead of “drag” as contact is made. The round surfaces result inindirect force transfers causing the gears to push apart as the “roll”effect moves the contact points above and below the direct line forces,thereby causing the deflection seen in FIG. 4.

Referring now also to FIGS. 7-9 in the drawings, a figure eight pinionbearing support 103 is integrally formed in the power end frame plate105. In the contemplated embodiment, support 103 is welded directly tothe frame plate 105. Thus, the support slides within the openings 701,703 formed by the plate 105, which in turn are configured to receive thebull gear and pinion therethrough. Thereafter, the support 103 is weldeddirectly to the plate 105. The extra material and thickness of support103 provides significant advantages. As noted previously, deflection incrankshaft 101 results in excessive strain on the pinion bearings,excessive wear on the bull gear and pinion teeth, and excessive strainin the power frames. The support overcomes these disadvantages byproviding additional support and rigidity. One way this feature isachieved is by increasing the surface contact with the plate via thesupports, as depicted in FIG. 7.

To effectively handle the natural deflection forces generated by thehigh horsepower gear loads, the present application discloses the use ofsupport 103 integrally formed into frame plate 105. The use of support103 minimizes weight added to the overall power end compared toexternally detachable housings currently in use. The power end 104includes a frame plate 105 at opposing ends of its body. Crankshaft 101extends between each frame plate end. Use of support 103 on a single endof the power end is insufficient to handle the forces generated. In thepreferred embodiment, support 103 is used at both ends of the power endin communication with the frame support 105 and crankshaft 101.

FIGS. 8 and 9 further illustrate the contoured shape and manner ofassembly of support. 103 in communication with that of frame plate 105.In particular, FIG. 8 illustrates a drawing for support 103, while FIG.9 illustrates support 103 before and after installation and welding intoframe plates 105.

As depicted in FIG. 8, frame support 103 is a robust and wide insertshaped to resemble a figure eight. In the preferred embodiment, support103 includes a body 801 having a first circular end 803 integrallyjoined to a second circular end 805 via a transition member 807. Firstend 803 forms an opening 809 that receives the bull gear, while secondend 807 forms an opening 811 that receives a pinion gear. As shown, bothopening 809, 811 are coaxially aligned with each other.

In FIGS. 9A-9C, the assembly of plate 105 and support 103 are shown. Inthe contemplated embodiment, support 103 is welded inside the thinnerouter power frame plates 105. By welding, support 103 is retrofittablewith existing frame plates 105. Also, frame plates 105 may be integrallyformed with support 103 to save the welding time during construction.Inner surface 107 of support 103 provides a full and rigid surfacecontact support for the pinion bearings. By displacing the forces actingupon frame plate 105 through crankshaft 101, the pinion bearings areproperly supported and can handle the large naturally occurringseparation forces generated by the bull and pinion gears.

Referring now to FIGS. 10 and 11 in the drawings, a support 1001 isshown in accordance with an alternative embodiment of the presentapplication. It will be appreciated that support 1001 is substantiallysimilar in form and function to support 103 and hereby incorporates oneof more of the features discussed above.

In the contemplated embodiment, frame support 1001 is a robust and wideinsert shaped to resemble a figure eight. In the preferred embodiment,support 1001 includes a body 1003 having a first circular end 1005integrally joined to a second circular end 1007 via a transition member1009. First end 1005 forms an opening 1011 that receives the bull gear,while second end 1007 forms an opening 1013 that receives a pinion gear.As shown, both opening 1011, 1013 are coaxially aligned with each other.

One of the unique features of support 1001 is the use of a flange 1015that extends from body 1003 and is configured to engage with a frontsurface 1101 of plate 105, as shown in FIG. 11. In the preferredembodiment, the flange 1015 is welded to the front surface 1101;however, alternative embodiments could use different types of fasteningmeans, e.g., bolts to secure the support to the front surface. Thus, inthe contemplated embodiment, the support 1001 could be used to retrofitexisting plate 105 embodiments by merely placing the support on thefront surface and thereafter welding the flange thereto.

Use of the supports 103, 1001 on both ends of the power end have manyadvantages, including at least the following: (1) increasing bull gearand pinion service life; (2) increasing pinion bearing service life; (3)reducing catastrophic pinion bearing and failures; (4) eliminating powerframe crack failures caused by gear separation forces; and (5) reducingpower end horse power loses due to reduced gear deflection, whichresults in less friction.

The particular embodiments disclosed above are illustrative only, as theinvention may be modified and practiced in different but equivalentmanners apparent to those skilled in the art having the benefit of theteachings herein. It is therefore evident that the particularembodiments disclosed above may be altered or modified, and all suchvariations are considered within the scope and spirit of the invention.Accordingly, the protection sought herein is as set forth in thedescription. It is apparent that an invention with significantadvantages has been described and illustrated. Although the presentinvention is shown in a limited number of forms, it is not limited tojust these forms, but is amenable to various changes and modificationswithout departing from the spirit thereof.

1. A power end assembly, comprising: a power end having a bull gear anda pinion gear; and a frame plate coupled to the power end and having apinion bearing support, wherein the pinion bearing support has a firstcircular end integrally joined to a second circular end by a transitionmember, wherein the first circular end has a first opening configured toreceive the bull gear therethrough, wherein the second circular end hasa second opening configured to receive the pinion gear therethrough, andwherein the frame plate and the pinion bearing support are integrallyformed as a single piece such that a thickness of at least a portion ofthe pinion bearing support is greater than a thickness of at least aportion of the frame plate.
 2. The assembly of claim 1, wherein adiameter of the first opening is greater than a diameter of the secondopening.
 3. The assembly of claim 1, wherein the pinion bearing supportextends from an interior surface of the plate.
 4. The assembly of claim1, wherein the pinion bearing support extends from an exterior surfaceof the plate.
 5. The assembly of claim 1, wherein the first and secondopenings are coaxially aligned with each other.
 6. The assembly of claim1, wherein the transition member is disposed between the first circularend and the second circular end.
 7. The assembly of claim 1, wherein theframe plate comprises a pair of frame plates coupled to opposite ends ofthe power end.
 8. The assembly of claim 7, further comprising acrankshaft extending between each frame plate and configured to rotateat least one of the bull gear and the pinion gear.
 9. A power endassembly, comprising: a power end having a bull gear and a pinion gear;a frame plate coupled to the power end and having a pinion bearingsupport, wherein the pinion bearing support has a first end having afirst opening, a second end having a second opening, and a transitionmember disposed between the first end and the second end, wherein thefirst opening is configured to receive the bull gear therethrough,wherein the second opening configured to receive the pinion geartherethrough, and wherein the frame plate and the pinion bearing supportare integrally formed as a single piece to increase surface contact ofat least one of the bull gear and the pinion gear with the frame platevia the pinion bearing support.
 10. The assembly of claim 9, wherein athickness of at least a portion of the pinion bearing support is greaterthan a thickness of at least a portion of the frame plate.
 11. Theassembly of claim 9, wherein the pinion bearing support extends from aninterior surface of the plate.
 12. The assembly of claim 9, wherein thepinion bearing support extends from an exterior surface of the plate.13. The assembly of claim 9, wherein the first and second openings arecoaxially aligned with each other.
 14. The assembly of claim 9, whereinthe frame plate is thinner than the pinion bearing support.
 15. Theassembly of claim 9, wherein a diameter of the first opening is greaterthan a diameter of the second opening.
 16. The assembly of claim 9,wherein the frame plate comprises a pair of frame plates coupled toopposite ends of the power end.
 17. The assembly of claim 16, furthercomprising a crankshaft that extends between each frame plate and isconfigured to rotate at least one of the bull gear and the pinion gear.